1. Field of the Invention
This invention relates to a means for guiding a tap straight into a pre-drilled hole. In order to prevent misalignment, breaking of taps, and improperly threaded holes, it is necessary to provide for correct alignment of the tap with respect to the hole. The center line of the tap should be congruent to the center line of the hole to be tapped during the entire tapping operation.
2. State of the Art
This invention relates to a manual tap guide which is intended for use with small production facilities, or for homeshop use where high quantity production is not required, but where correct alignment is desired. U.S. Pat. No. 3,267,501 (Wright) shows a manually operated machine tool or tap guide which may be used to tap holes in a flat plate. This guide includes only one degree of freedom which is movement of the arbor in a vertical direction. Any adjustment to the tap hole will require movement of the entire assembly. U.S. Pat. No. 804,869 (Mitchell) shows a typical vertical alignment device which includes an arbor fixed with respect to the work piece. U.S. Pat. No. 1,693,129 (Willis) shows another hand-operated vertical shaft tool for alignment of a work piece with the tool. Willis does provide for adjustment of position along a slide or rack 7. U.S. Pat. No. 889,273 (Thomas) shows a boring jig which may be used to align a tool with a hole to be bored or machined. U.S. Pat. No. 393,511 (Leland) shows a typical tap driving head of the type that would be used on a drill press for running and guiding a tap.
In addition to the above-enumerated U.S. patents, the inventor of the invention herein has used in his machine shop a tap guide which includes a solid heavy metal base, a vertical member, a horizontal member along which the position of the tap guide can be adjusted, and a vertical arbor for rotating of a tap.